According to https://www.reddit.com/r/linux/comments/9wd41c/linux_on_dex_beta_is_live_need_signup/
it appears that Linux on DeX is based on LXC or LXD.
- The package name is https://play.google.com/apps/testing/com.samsung.android.lxd which includes lxd.
- A user, Dragon5232, says It’s an LXC container that can run alongside basic Android services. It’s the same kernel, not hypervised (although technically the kernel is hypervised by the TEE running in the TrustZone).
More on Linux on DeX,